Sash balance



E. L. GRUPP SASH BALANCE Oct. 23, 1956 Filed May 13, 1953 svNNNWN INVENTOR. 55144420 I GQUPP,

United States Patent SASH BALANCE Edward L. Grupp, Glendale, Calif. Application May 13, 1953, Serial No. 354,743

9 Claims. (Cl. 16-198) This invention relates to sash balances, and more particularly to a readily adjustable sash balance for counterbalancing and facilitating raising and lowering of window sash and other vertically movable windows, screens. and the like.

Prior sash balances have usually been made from pressed sheet metal parts or elements in different weights and styles, each weight and style being used for a particular weight and style of window sash. Each prior balance was therefore preset at the factory for the particular weight and style of window upon which it was to be used. The effective variation from the preset weight was usually not more than plus or minus two pounds. Thus the range of utility of prior sash balances was extremely limited, and in the event balances of wrong weight and style were delivered to aconstruction job, they could not be employed because they would be either too light or too heavy for the window sash requirements. To meet the normal range of variation found in usual building construction, approximately six or eight different weights and styles of sash balances were manufactured.

In addition, prior sash balances were relatively large, that is, were relatively wide and thick and required window frame members. of relatively heavy construction. The prior sash balances became rapidly worn in use, and because they were often inaccurately assembled from the sheet metal parts, the forces acting on the balances would cause the winding drums to.wobble and stick, or the cable would slip from the winding drum and become wedged between the drum and an adjacent part of the balance. When an installed sash balance was thrown out of kilter in the above manner, the balance was practically impossible to repair and the entire balance had to be replaced. Assembly of pressed metal sash balances was difficult, was not adapted toautomatic assembly and labor costs were high. The cost of tooling for the production of pressed metal balances, including the great many dies for the production of the large number of small parts required, was an expensive burden to the manufacture of such prior pressed metal sash balances.

This invention is directed to an improved sash balancein such a manner that a minimum amount of machining is required. The cast sash balance provides smooth surfaces in the completed balance and eliminates cuts and hazards resulting from prior pressed sheet metal constructions. A sash balance embodying the present invention is capable of assembly in a simple and rapid manner because the several parts may be arranged in a relaxed condition and tensioned after the balance has been assembled.

The present invention contemplates an improved sash balance which is relatively thin, as compared to prior balances, and which is provided with means for readily adjusting the balance to deliver a selected degree of tension. As a result, the sash jbalancetof thisinvention 1 may be adjusted to lifting a six-pound, eight-pound, tenpound or even a fourteen-pound window sash. The sash balance of this invention may be installed in relaxed or unwound condition by a finish carpenter, and after having been properly fitted into the frame and attached to the sash, may be easily tensioned so as to most effec tively maintain a window in every position from fully open to fully closed. Thus installation of the present sash balance is facilitated and operation may be maintained at a maximum level of efficiency.

Therefore the primary object of this present invention is to disclose and provide an adjustable sash balance of either single or dual-type, giving rise to one or all of the advantages above recited.

The invention particularly contemplates a single sash balance which is readily adapted for installation in either the head or side member of a window frame.

An object of this invention is to provide an adjustable sash balance which is made from a minimum number of parts, preferably of lightweight metal alloys cast in desired form.

A further object of this invention is to provide a sash balance wherein the several parts of the balance are arranged for producing exceptionally smooth operation and for facilitating rapid production and assembly of the balance.

Still another object of this invention is to disclose and provide a sash balance in which the cable-carrying reel member is mounted in novel manner so as to be rotatably mounted for maximum smoothness of operation under varying conditions of load imposed thereon by the cable wherein wobbling or sticking of the reel member is eliminated.

This invention contemplates an improved sash balance of relatively thin section or depth and having virtually only three major integrally cast parts, namely, a housing, a reel member and a cover plate.

A still further object of this invention is to design a sash balance which facilitates the casting of the several parts and which utilizes a minimum of metal.

Another object of the invention is to provide adjustable tensioning means for the spring means used therewith whereby the balance may be readily set to a selected tension in the field.

A still further object of this invention is to disclose a sash balance having various parts designed for convenient casting as by a pull operation and without employing cores or special dies. f

The invention contemplates a reel or ring member for winding the cable which is provided with a slightly tapered or inclined cable winding surface upon which the cable may be wound without jamming or overlapping of the cable turns.

Other objects and advantages of this invention will be readily apparent from the following description of the drawings in which an exemplary embodiment of this invention is shown. a

In the drawings:

Fig. 1 is a perspective viewof a single-type sash baljamb of a frame.

Fig. 6 is a fragmentary, perspective view of a singletype balance illustrating a modification of adjustable tension locking means for said balance.

;Fig. 7 is a fragmentary perspective view of another modification of an adjustable tension locking means for a sash balance.

Referring first to Figs. 4 and 5, there are illustrated .two different installations of a single-type sash balance generally indicated at 10. In Fig. 4 the sash balance is installed in a recess 11 provided in a head 12 of a window frame, the recess being located adjacent to a jamb member 13 of said frame. In Fig. the sash balance is installed in a recess 14 provided in the side jamb member of .the frame adjacent the ,top thereof. The single sash balance 19 is provided with a face plate 16 having a longi- :tudinally extending slot 17 having enlarged end openings 17a and 17b for the passage therethrough respective- ,ly of .a cable 18 of the balance. The opening 17a accommodates cable 18 when installed as in Fig. 4 for positioning the cable closely adjacent to the jamb member 13. The adjacent end portion of face plate 16 may extend :between the top face of jamb member 13 and the head 12 for securing and positioning one end of the balance. A single screw through a port in the other end of the face plate and into the head 12 will thus firmly secure the balance.

. The opening 17b affords or permits passage therethrough of the cable 18 when installed in a recess in the jamb member 13, end ports in the face plate receiving securing screws asin Fig. 5. Thus the single sash balance 10 isreadily adapted to installation in a window frame in such a manner as to provide a most efficient and effective employment of the sash balance.

The sash balance 19 generally comprises an integral,

hollow housing 20 having a cylindricalcharnber 21 having one end open and which receives therein a cylindrical open-ended ring member 22 upon which cable 18 may be wound. A circular cover plate 23 extends over the opening of chamber 21 and is cooperable with tension adjusting and locking means carried by the housing for regulatingjthe tension of a helical spring 24 carried within the r ugrnember 22. The helical spring 24 is arranged to be connected at its outer end 25 to the ring member and connected at its inner end 26 to the cover plate 23 so that turning of the cover plate will tension the spring and the tension will beheld by-the tension locking means.

The housing 20 may comprise integrally cast, cylindrical side walls 28 defining therewithin the cylindrical chamber 21 and an end wall29 closing one end of chamber 21 and integral with side walls 28. The opposite end of chamber '21 is open. The side walls 28 may include an integral, lateral extension, forming the face plate 16 at one end of the housing, the face plate 16 lying in a plane perpendicular to end wall 29. The face plate 16 may be provided at opposite ends with ports 30 for installing the sash balance in a window frame member as by wood screws. The face plate 16 may be provided with a smooth, fiat, outer surface 31 which is adapted to be installed flush with the adjacent face of a frame member. While the face plate 16 is illustrated on this single-type sash balance as being provided on an end of the balance, 'it is understood that end wall 29 may serve as a faceplate when the construction of this balance is employed in a dual-type sash balance and wherein the balance is mounted ina side frame member in a relatively shallow, elongated recess.

The side walls 28 may also include an end portion 33 adjacent to face plate 16 of relatively thick, metal section for carrying spring tension adjusting and locking means, such means beingdescribed in detail hereinafter.

Means for rotatably and coaxially positioning cover plate 23 in the open end of chamber 21 may comprise an axial, upstanding post .or stub axle'34 integrally formed on end wall 29 and having a length approximately equal to the depth of chamber 21. Encircling the base of' post 34 may be an annular, shallow boss 35. The top end of post 34 is provided with a reduced portion 36 adapted to be peened over as later described. The cover plate 23 is provided with a depending, hollow, axial, open-ended, integral sleeve 37 arranged to be sleeved over post 34 and having its bottom open end adapted to receive the boss 35 so as to provide a bearing at 38. Adjacent the top end of sleeve 37 is provided a radially, inwardly directed, annular flange 39 haying an inner, circumferential edge adapted to bear as at 40 on the adjacent, annular surface of post 34 slightly below a shoulder 41 defining the reduced portion 36 of the post. The axially spaced bearings at 38 and 40 of cover plate 23 with the post 34 serves to accurately mount the cover plate for rotation with respect to the cylindrical chamber 21 in the housing.

Bearing means for rotatably and accurately mounting the ring member 22 within chamber 21 and between end wall 29 and cover plate 2 3 may include oppositely and outwardly facing inner, marginal, annular recesses v43 and 44 adapted ,to respectively receive annular, inwardly facing ribs 45 and 46 carried by the cover plate and end wall 29 respectively. It should be noted that the annular ribs 45 and46 are of virtually the same diameter and are located adjacent outer margins of the circular cover plate 23 and cylindrical chamber 21. The cooperable engagement of these ribs 45 and .46 with the recesses 43 and 44 thus provide a relatively large, accurately determined bearing affording smooth operation of the ring member when it is caused to rotate within the balance during use.

The ring member 22 is also provided with a bottom, external, circumferential flange 47 adapted to be received within the annular space afforded between the annular rib 46 and theinternal wall of the cylindrical chamber 21. The flange 47 serves to prevent the cable 18 from being jammed or lodged between the ring member 22 and end Wall 29. i V

The annular rib 45 on the cover plate 23 defines with an outer, depending, circumferential, thickened metal section of the cover plate 23, an annular groove 48 which receives an outer, annular edge portion 49 of ring member 22 so as to prevent jamming of the cable between ring m e 2.2 a d c ve P t The helical spring 24 may be connected to reel member 22 by its outwardly turned end 25 which is received within a' slot 50 formed on the inner surface of the ring member 22 by an inwardly extending portion 51. The inner end 26 of the spring 24 may be conveniently connected to the cover plate 23 by reception of end 26 within a longitudinally extending, open-ended slot 52 provided in sleeve 37.

The cable 18 may be connected to the ring member 22 by inserting inner end 54 of the cable first into and through port 5 5 in the portion 51 of the ring member '22 and then bending said end upwardly and downwardly into a top hole 56 provided in the portion 51. The cable 18 maybe wound around the ring member 22 and its free end may be passed through slot 17 for connection to a shoe or glide 57 of angle shape in any suitable manner. The glide 57 is adapted to be attached to the bottom corner of a windowsash to be balanced.

Means for adjustably tensioning spring 24 within ring member 22 and for maintaining said spring under the selected tension may comprise a plurality of circumferentially arranged and spaced, depending teeth 59 provided on the outer depending circumferential section of cover plate 23. The teeth 59 are received within an outwardly facing inner circumferential annular recess 60 formed on side walls 28 at the open end of chamber 21.

An angularly arranged slot 61 provided in end portion 33 of the housing opens into fthe chamber 21 and is provided with a vertical bore 62 intermediate its ends. Slot 6'1 accommodates a flat locking element 63 having a pair of parallel, open-ended slots 64'adapted to receive and position a coil spring 65, said spring 65 being received and seated in bore 62. Locking element 63 includes a shoulder 66 which is positioned adjacent the inner end of slot 61 and is biased upwardly by the spring into engagement with the downwardly facing teeth 59 on cover plate 23. The outer face of the cover plate 23 may include a plurality of circumferentially spaced indents or holes 67 adapted to receive a pointed end of a suitable tool for facilitating rotation of the cover plate against the tension of the spring.

The entire assembly of the sash balance may be secured by a washer 69 sleeved over the reduced end portion 36 of the post 34 and received in the upper circular opening 70 above flange 39. The reduced portion 36 may then be peened over the washer 69 so as to secure the entire assembly.

It will be readily apparent that tension of the spring 24 may be conveniently adjusted by rotating the cover plate 23 to tighten the helical spring. The locking element 63 is continuously biased upwardly against teeth 59 and as the cover plate 23 is rotated, the locking element engages teeth 59 and maintains the spring under the selected tension when rotation of the cover plate is completed. It may be noted each tooth 59 includes a relatively long, sloping face which facilitates rotation of the cover plate when engaged with the locking element 63.

In the event it is desired to decrease tension of the spring, the locking element 63 may be depressed by inserting a suitable tool through the top open end of bore 62 and thus disengage the locking shoulder 66 from the teeth 59. Pressure against the cover plate or holding the plate against rotation by a tightening tool engaged in indents 67 will prevent snap unwinding of the spiral spring.

It will be readily apparent from the above description that assembly of a sash balance embodying this invention is facilitated by the particular construction of the several parts thereof. The housing may be placed upon a suitable work table with the open end of chamber 21 facing upwardly. The ring member 22 with the cable wound thereon may be dropped into the cylindrical chamber 21 and positioned therein by the annular rib 46 and flange 47. A relaxed spring 24 may then be inserted into the ring member 22 in relaxed condition so that end 25 engages the slot 50 on the ring member. The cover plate may then be placed over the open end of chamber 21 and the slot 52 of the sleeve 37 may be aligned with the inner end 26 of the spring 24. Insertion of sleeve 37 into the chamber thus engages the inner end 26 of the spring 24 and the sleeve is accurately positioned with respect to the post 34. The annular rib 45 on the cover plate is aligned and drops into the annular recess 43 on the cylindrical member. The washer 69 is then dropped over the reduced portion 36 of the post and is secured by peening the portion 36 as by striking the same with a hammer. The relaxed spring may then be tensioned as above described after the assembly is completed, the desired tension being held by the engagement of the locking element with the teeth on the cover plate.

It should be also noted that the outer circumferential face of the ring member is tapered slightly inwardly so that the diameter adjacent flange 47 is greater than the diameter at the edge portion 49. As the cable 18 is wound from the smaller diameter to the larger diameter or vice versa, the taper of the outer ring surface serves to guide the cable for preventing overlapping of adjacent turns of the cable which might cause jamming.

The modification shown in Fig. 6 discloses a single-type sash balance which includes the detailed structure described above with respect to the single-type sash balance but illustrates a modification of the tension adjusting and locking means.

In Fig. 6, a cover plate 23' is providedwith an outer circumferential depending gear toothed portion 75. A thickened metal portion 33 extending between the walls 28 and face plate 16 may have an angularly disposed bore 76 formed therein which opens along one side into the chamber 21'. A worm threaded screw 77 is received by the bore for meshing with the gear portion of the cover 23. The head 78 of the screw 77 is accessible from the face plate 16. Thus turning of screw 77 by a suitable tool such as a screwdriver will rotated the cover 23' and vary the tension of the spring within the sash balance. The angular relationship of the screw 77 with respect to the gear portion 75 provides self-locking of the cover 23 against rotation and prevents release of spring tension. Since the screw head 78 is accessible from the face plate 16, the tension of the sash balance may be adjusted even after installation.

In Fig. 7 a still diiferent modification of the tension adjusting and locking means is shown for a sash balance of dual type wherein face plate 16" lies in a plane at right angles to the axis of rotation of the reel member.

As in Fig. 6, a cover plate 23", is provided with an outer circumferential depending gear toothed portion 75'. The thickened metal portion of the sash balance may be provided with a suitable, radially, inwardly extending bore adapted to receive a dual-type gear 80. The dual gear 80 includes an inner gear 81 having teeth meshed with gear portion 75' of the cover plate. An outer, second gear 82 has teeth meshed with a worm threaded screw 83. The worm screw 83 is carried in a vertically extending bore in the thickened metal portion and presents an outer slotted head 84 which may be readily engaged by a screwdriver.

Rotation of screw 83 by a screwdriver will rotate'the dual gear 81 and cause rotation of the cover plate. 23" and thereby tension the spring of the balance which is connected thereto as described in the prior modification. The dual gear 80 and the worm screw 33 are angularly arranged so that upon release of a screwdriver, the gear teeth of the dual gear 81 and worm thread on the screw 83 lock to prevent rotation of cover plate 23'. Thus automatic locking is provided for the tension adjusting means. The tension of the sash balance may thus be readily adjusted after installation in a frame member.

While the modification in Fig. 7 shows the headed screw 83 facing toward the front face of a dual-type sash balance, it is understood that screw 83 may be reversed in position so that the slotted head :84 is accessible to a screwdriver from the rear face of the sash balance.

It will be understood that the Worm screw and gear arrangements of the modifications may be used in place of the biased locking element described in the first modification and that either of these means for adjusting the tension of the balance may be employed on either single or dual-type balances.

The tension means may, if desired, be preset at the factory for a selected weight and size of sash. In the event the balance is required for use on. a difierent weight and size of sash, the balance may be readily adjusted in the field to accommodate the diiferent sash. Preferably the spaced teeth on cover plate 23 are so arranged that turning of the cover plate to engage an adjacent tooth will represent a selected fraction of a pound of tension being applied to the spring. For example, turning the cover plate so as to move three teeth past the locking element may represent an increase or decrease of one pound of tension applied to the spring. Thus by counting the number of clicks that. the locking element makes with the teeth, a carpenter may readily adjust the tension of the balance to a selected number of pounds.

It should be particularly noted that the housing, reel member, and cover plate may be conveniently cast and that the design thereof utilizes a minimum amount. of metal. In addition, the design of the several parts facili- .tatesefficientand .rapid productionand assembly of sash balances embodying this invention.

The means for rotatably mounting the cylindrical ring member shouldbe particularly noted because the bearing surfaces .upon which the ring member is rotated are located adjacent :the outer circumference of the ring member and are in direct opposed relation, therefore pro- :viding accurate, non-Wobbling mountingof the ring member. The cooperative engagement of the annular ribs on the cover plate and the end wall of the housing with the complementary recesses provided on the ring member prevents any twisting or misalignment of the ring member duringoperation fromunusual loads which might be applied by the cable to the ring member.

The tension-adjusting means is located adjacent the outer circumference of the cover plate or the rotatable elements of the sash balance so that .a maximum leverage is available when the cover plate is rotated for tensioning the spring. This maximum leverage is also effective for holding the cover plate against rotation when under selected tension.

The slotted face portion of the single-type balance provides a simple, effective, convenient arrangement for guiding the cable of the balance when the balance is installed in either the head member or side member of a window frame. The application of such a singletype balance is thus made more versatile.

It will be understood that various modifications and changes coming within the scope of the appended claims are embraced thereby.

I claim:

1. In a sash balance, the combination of: a housing having integral side walls and an end wall defining a cylindrical chamber provided with a circular open end; apost integral with said end wall and coaxially extending into said chamber; a circular cover plate for the open end and including an integral, central, hollow sleeve receiving said post and having an edge margin bearing on the base of said post and an internal flange bearing on said post adjacent the top thereof; an open-ended ring member received within said chamber in coaxial relation with said post and having oppositely and outwardly facing inner circumferential recesses; circular ribs formed on said cover plate and on the end wall of said housing extending into said oppositely facing recesses to afford bearing for said ring member; an outwardly directed flange integral with one edge of said ring member; a cable wound around the ring member; a plurality of circumferentially spaced teeth carried by the cover plate and received within a circumferential recess formed in the side walls of said housing; a locking element carried by the housing and biased into engagement with said teeth; the outwardly facing surface of one of said walls providing a face plate for said balance; said open-ended ring member being provided with an external tapered surface and said face plate being provided with spaced openings and a slot interconnecting said openings for passage of the free end of said cable therethrough whereby said balance is adapted to be selectively installed in a window frame.

2. In a sash balance, the combination of: a housing having integral side walls and an end wall defining a cylindrical chamber provided with a circular open end; a post integral with said end Wall and coaxially extending into said chamber; a circular cover plate for the open end and including an integral, central, hollow sleeve receiving said post and having an edge margin bearing on the base of said post and an internal flange bearing on said post adjacent the top thereof; an open-ended ring member received within said chamber in coaxial relation with said post and having oppositely and outwardly facing inner circumferential recesses; circular ribs formed on said cover plate and on the end wall of said housing extending into said oppositely facing recesses to afford bearing for said ring member; a cable wound around the ring member; a plurality of circumferentially spaced teeth carried by the cover plate and received within a circumferential recess formed in the side walls of said housing; a locking element carried by the housing and biased into engagement with said teeth; said open-ended ring member being provided with an external tapered surface; and the outwardly facing surface of one of said walls providing a face plate for said balance.

3. In a sash balance, the combination of: a housing having integral side walls and an end wall defining a cylindrical chamber provided with a circular open end and an end closed by said end Wall; a cover plate for said circular open end; means to axially position the cover plate with respect to the cylindrical chamber; said positioning means including an axial, outwardly extending post integral with the end wall and a hollow, central sleeve carried by the cover plate sleeved over said post and having an internal, ported flange bearing against said post adjacent its end; the end edge margins of said sleeve bearing on an enlarged base for said post; an openended ring member enclosed within said housing between the cover plate and said end wall; means for rotatably mounting said ring member including outwardly and oppositely facing recesses on inner margins of said ring member and cooperable, inwardly facing circular ribs on said end Wall and said cover plate; a spiral spring means within said ring member having one end connected to said ring member and the other end connected to said sleeve on the plate; said ring member being provided with an external tapered surface; and means for locking said cover plate against rotation comprising teeth on said cover plate and a biased locking element carried by said side walls.

4. In a sash balance, the combination of: a housing having integral side Walls and an end wall defining a cylindrical chamber provided with a circular open end and an end closed by said end wall; a cover plate for said circular open end; means to axially position the cover plate with respect to the cylindrical chamber; said positioning means including an axial, outwardly extending post integral with the end wall and a hollow, central sleeve carried by the cover plate sleeved over said post and having an internal, ported flange bearing against said post adjacent its end; the end edge margins of said sleeve bearing on an enlarged base for said post; an open-ended ring member enclosed within said housing between the cover plate and said end wall; means for rotatably mounting said ring member adjacent the circumference thereof including outwardly and oppositely facing recesses on inner margins of said ring member and cooperable, inwardly facing circular ribs on said end wall and said cover plate; a spiral spring means within said ring member having one end connected to said ring member and the other end connected to said sleeve on the plate; and means for maintaining tension on said spring means including a locking element carried by the housing cooperable with means on said cover plate.

5. In a sash balance, the combination of: a housing having integral side walls and an end wall defining a cylindrical chamber provided with a circular open end and an end closed by said end wall; a cover plate for said circular open end; means to axially position the cover plate with respect to the cylindrical chamber; an open-ended ring member enclosed Within said housing between the cover plate and said end wall; means for rotatably mounting said ring member including outwardly and oppositely facing recesses on inner margins of said ring member and cooperable, inwardly facing circular ribs on said end wall and said cover plate; a spiral spring means Within said ring member having one end connected to said ring member and the other end connected to said plate; and means for maintaining tension on said spring means including a locking element carried by the housig cooperable with means on said cover plate.

6. In a sash balance the combination of: a housing having side walls and an end wall defining a cylindrical chamber provided with a circular open end and an end closed by said end Wall; a cover plate for said circular open end; means to axially positicn the cover plate with respect to the cylindrical chamber; an open-ended ring member enclosed within said housing between the cover plate and said end wall; means for rotatably mounting said ring member including outwardly and oppositely facing recesses on margins of said ring member and cooperable inwardly facing circular means on said end wall and said cover plate; a spring means within said ring member having one end connected to said ring member and the other end connected to said plate; and means for maintaining tension on said spring means including a lockim element carried by the housing cooperable with means on said cover plate.

7. In a sash balance the combination of: a housing having side walls and an end wall defining a cylindrical chamber provided with a circular open end and an end closed by said end wall; a cover plate for said circular open end; means to axially position the cover plate with respect to the cylindrical chamber; an open-ended ring member within the housing between the cover plate and said end wall; means for rotatably mounting said ring member including outwardly and oppositely facing bearing means on margins of the ring member and cooperable inwardly facing bearing means on said end wall and cover plate; a spring means within said ring member having one end connected to said ring member and the other end connected to said plate; a locking element carried by said housing and a cooperable locking means on said cover plate for holding said spring means under selected tension.

8. A sash balance as claimed in claim 7 including a tapered external surface on said ring member.

9. A sash balance as claimed in claim 7 including a cable wound around said ring member; said housing being provided with a face plate having spaced openings and a slot interconnecting said openings for selective passage of the free end of said cable therethrough.

References Cited in the file of this patent UNITED STATES PATENTS 479,150 Kimball July 19, 1892 820,962 Erb May 22, 1906 891,853 Neren June 30, 1908 1,626,018 Wagniere Apr. 26, 1927 1,762,821 Kersting June 10, 1930 2,051,412 Lewis et a1. Aug. 18, 1936 2,679,659 Grupp June 1, 1954 

